Housings from sizes 3076, 3168 and 3264 upwards are supplied in two designs:

Housings with the suffix F have a bearing seat that matches the bearing width. These housings should be used for spherical roller bearings in the locating position and CARB toroidal roller bearings.

Housings with the suffix L have a bearing seat that is wider than the bearing. These housings should be used for spherical roller bearings in the non-locating position. The possible axial displacement is at least 20 mm.